Planter Technology Contained Irrigation Systems at Waterforce in Nerang on Queensland's Gold Coast.

Planter Technology’s Controlled Watering System or CWS is a Contained Irrigation system. Based on a concept that reaches back to 1972.
They were the first company to perfect a system to help maintain pots and plants of all types, and are still the leading player in the marketplace. The Controlled Watering System has been used in hundreds of thousands of installations all over the world, and has proven itself to be the easiest to use, most reliable system in the world.

Their Product Range: Container Systems, Planters with Built-in Irrigation, Thermoplastic Planter Liners and Planter Liners with Built-in Irrigation.

A brief written explanation of the system. The Controlled Watering System consists of a double-walled container (or a modular reservoir, in the case of the Controlled Water Modular), with a moisture sensor extending from the top of the wall. Water is filled through a hole at the top of the reservoir, and closed with a stopper of some sort.

Water flows into the soil mass through small holes at the bottom of the reservoir. The water wicks its way up through the soil (using the soil’s own natural capillary action) until it reaches the white tip of the moisture sensor. The sensor absorbs water from the soil, and blocks the passage of air through the tube.

A vacuum develops above the water in the reservoir, which prevents water from flowing out the holes. The valve action of the sensor provides for an optimal balance of moisture and oxygen in the soil. As the plant draws moisture from the soil, the sensor begins to dry, and releases air into the reservoir. The watering process starts all over again.